The disc plowshare comprises a main disc (8) to plow a furrow in the ground. A secondary disc (9) keeps the furrow open over a sufficient distance to place one or more grains. A support part (7) supports the discs to rotate freely and be inclined so that their peripheries meet in a region (A) in the front bottom part of the plowshare. A sealing ring (31) on the discs seals the region where the edges of the discs come into close proximity with each other.
